Entropy Generation Minimization of Confined Nanofluids Laminar Flow Around a Block

Abstract

According to the importance of cooling and heating process of a solid object, entropy generation in confined flow around a block is studied. In the current study, numerical simulation of laminar flow and heat transfer of nanofluids with nanoparticles of different shapes is considered. The nanofluids are water mixture with either Al2O3 nanoshperes or carbon nanotubes (CNTs). The incompressible Navier-Stokes and energy equations are solved numerically in a body fitted coordinates system using a control volume technique. The flow patterns and temperature fields for different values of the particles concentrations are examined in detail. Furthermore, the effects of nanoparticles shape and concentration on the heat transfer are studied. Furthermore the influences of nanofluids on pressure drop and pump power is examined. On the other hand, the entropy generation minimization is considered as the optimization criterion. The results indicate that in most cases the nanofluids enhance the heat transfer as well as pressure drop. It is interesting to note that the shape of nanoparticles is critical in determining the key mechanism of heat transport in nanofluids. Nanofluids with cylindrical nanoparticles exhibit a greater increase in heat transfer compared with nanofluids having spherical shape nanoparticles.

Entropy Generation and Heat Transfer Performances of Al2O3-Water Nanofluid Transitional Flow in Rectangular Channels with Dimples and Protrusions

“…Cho et al [40] conducted an investigation on natural convection of water-based nanofluids in an enclosure with wavy walls, and three different types of nanoparticles, Cu, Al 2 O 3 and TiO 2 , are adopted, respectively. Boghrati et al [41] achieved a numerical investigation on the entropy generation of the Al 2 O 3 -water and carbon nanotubes-water nanofluids flows through two horizontal parallel plates with a rectangular barrier. Sarkar et al [42] conducted a study on the entropy generation of water-based Al 2 O 3 and Cu nanofluids mixed convection flowing past a square barrier in the middle of two parallel plates.…”

Second Law Analysis of Nanofluid Flow within a Circular Minichannel Considering Nanoparticle Migration

“…Boghrati et al [31] evaluated entropy production due to the flow of water-based carbon nanotubes (CNTs) and Al 2 O 3 nanoparticles inside parallel plates. Between the two plates, a rectangular barrier was situated such that the nanofluid can flow around the barrier.…”